Carburetor



w. H. WEBER March 1, 1932.

CARBURETOR 2 Sheets-Sheet Filed Sept. 9, 1927 avwemtoz Patented Mar. 1,1932 wamnnf tywnnnnrownmaon, MICHIGAN, ASSIGNOR 'ro iinrnorr Lnnmoaroaor person,

MICHIGAN, A CORPORATION OF MICHIGAN CARBURETOB n, filed September 8,1927. Serial No. 218,407.

I My invention is for a new and useful improvement in carburetors, andrelates more particularly to means by which the supplies of air and fueladmitted to the mixing chamher may be controlled.

An object of my invention is to provide a carburetor which will operateefiiciently over the complete range of engine speeds.

Another object is to provide a carburetor m in which the response of theair and fuel control means to movement of the throttle valve may beregulated.

The invention consists in the improved construction and combination ofparts, toqbe more fully described hereinafter, and the novelty of whichwill be particularly pointed out and distinctly claimed.

In the accompanying drawings, I have fully and clearly illustrated apreferred embodi- 29 ment of my invention, to be taken as a part of thisspecification, and wherein- Figure 1 is a viewv in side elevation of myinvention, with parts broken away and partly in section;

Fig. 2 is a top plan view thereof;

Fig. 3 is an end view looking from the right of Fig. 1 and having partsbroken away andpartly in section;

Fig. 4 is a section on the line 4-4 of Fig. 2;

Fig. 5 is a detail view in section of the float chamber on the line 55of Fig. 3, and

Fig. 6 is a detail central sectional view of the fuel valve assembly.

Referring to the drawings by characters of reference, 1 designates,generally, a carburetor embodying my invention, and having a throttlebody 2 and a carburetor body 3. The throttle body 2 is fixed to thecarburetor body 3 in any desired manner, but

preferably by screws 4, and the union sealed y a gasket 4.

'VVithin the throttle body 2 is a mixing chamber 6 which may be of anydesired shape, and from which leads a mixture outlet passage 7. Anexternal flange 8 having bolt or screw holes 8 is provided at the end ofpassage 7 by which the carburetor 1 may be secured to an engine intakemanifold (not shown). The outlet passage 7 is controlled by a throttlevalve 9, preferably of .the plate or butterfly type,

which is carried by a shaft wall of passage 7 and receives an operatinglever 12 provided with a fixed stop 13 to limit opening'movement of thevalve 9 and with an adjustable stop 14 to limit closing movement of saidvalve. The stops 13 and 14 are limited in movement by engagement withopposite sides of an abutment 15 fixed on the wall of the passage 7.Beyond the valve 9 and opening through the wall of passage 7 adjacentthe flange 8, is apassage 16 for connection to a vacuum tank (notshtown) in-the fuel supply line to. the carbure or. I The carburetorbody 3 has an air chamber 17 supplied with air by a conduit or tube 18which is preferably detachably connected to the body 3. The air tube 18may, if desired, be connected to'a-n air heating means such as a stove(not shown) surrounding the engine exhaust pipe, as is well known in theart. In order to regulate the temperature of the incoming air throughtube 18, cold air Also carried by the carburetor body ass-a I fuelreservoir or float chamber 21 which maybe of any desiredconstruction,-and specifically forms'no part of my invention, except inso faras it provides for proper operation of the carburetor bymaintaining the fuel supply at a constant level at the carburetor. Inthe base 22 of the reservoir is a valvecontrolled inlet 23, which isopened and closed automatically by a valve 24 controlled by a float'25acting through levers 26 upon the valve stem 27. The levers 26 arepreferably supported on pivot pins 28, carried by the reservoir cover29; iquid fuelin the reservoir is maintained at atmospheric pressure bymeans of the atmospheric airinlet aperture 29*.

The air to be used in forming the combustible mixture is fed to chamber17 by the conduit 18, and is admitted to the mixing chamber 6 through aport 30 which is controlled by a conical suction-controlled air valve 31having a seat 32 about said port. Through valve 31 are a plurality ofair ducts 33 which converge to form a nozzle 34 which feeds into chamber6. Depending from and operatively connected to the valve 31 is a valvestem or fuel delivery member 35 having a longitudinal internal hollowbore 36 which opens at its upper end through a calibrated jet 37 intothe nozzle 34. Beneath the port 30 and within the air chamber 17 andsupported on the bottom wall thereof, is a boss 38 having an internalopen-ended guideway 39 in which the valve stem 35 has a free slidingfit. The stem 35 projects through the" lower end of the guideway 39 andinto a.dash-pot chamber 40 having an open bottom which is closed by acover 41, preferably secured to the chamber by screws or bolts 42.Within the chamber 40 and rigidly secured to the stem is a piston 43which has a slight clearance with the side walls of the chamber, say,.0025 inches. The piston 43 has a plurality of passages 44lead mgthrough it and which are provided with as check valves 45, preferably,but not necesfuel can only pass below the piston throughv the clearanceat the sides thereof, Fuel 131 fed to the chamber above the piston by aconduit 46 from the reservoir 21 (see Fig. 35 3). The hollow bore orpassage 36 in the stem 35 extends through the piston 43, but is sealedat its lower end by a disc 47 Fuel is fed from the top side of piston 43and into the passage or hollow bore 36 through pas- 40 sages 48, ofwhich but one is shown.

Depending from the cover 41 is a hollow sleeve 49 having a laterallyextending offset hollow boss 50 which is in communication with sleeve49. The boss 50 is open and internally threaded at one end, as at 51, toreceive a packing gland 52 having a journal bearing 53 for a shaft 54,packed at 55 by any suitable material which is secured in place by a nut56 and lock nut 57. One end of shaft 54 projects through and beyond thegland and carries a lever 58 secured on the shaft by a screw 59. Thelever has a stop arm 60 which contacts an adjustable abutment 61 carriedby the cover 41. A tension spring 62 having one end fixed to a lug 63 onthe carburetor body 3 and the other end fast to the arm normally tendsto rotate shaft 54 clockwise of Fig. 3 to maintain the stop arm 60 inengagement with its abutment 61. Operating means 60 (not shown) arepreferably connected to the lever 58, as at 59*, and extended to aposition adjacent the operatoryfor example, to the dash-board of a motorvehicle. Fixed on the opposite end of shaft 54 from lever 58 and withinthe hollow boss 50, is a toothed pinion 64, a portion of thecircumference of which projects through the communieating opening (notshown), and engages a toothed rack 65 which is longitudinallyreciprocable in the sleeve 49. The rack is preferably in the form of ahollow cylinder having an internal flange 66 and shoulder 67 forreceiving a metering pin or needle valve assembly (see Fig. 6). Thetapered valve or pin proper 68 has a depending valve stem or conduitmember 69 with a hollowbore or passage 70 which terminates at its upperor inner end adjacent the pin proper 68 and which is sealed at its loweropen end by a head 71. Around the head 71 is a circumferential groove 72which fits loosely for rotation into the center opening of a slottedsup- )orting washer 7 3. This much of the assembly is then passedthrough the hollow rack 65 until the washer 7 3 abuts the underside ofthe flange 66. The washer 73 and parts carried thereby are then fixed inthe rack in any desired manner, as by soldering, or the like, though Iprefer to do so by staking the shoulder 67 in tightly around the washer73, as at 67, see Fig. 6. The stem 69 extends upward through ahorizontally floating close iitting guide sleeve 74 carried by a plate75 fixed across the sleeve 49 in the plane of .cover41, and through aguide aperture 76 in the closure disc 47. The'tape1'ed valve gpm er 68extends up into the passage 36 and cooperates witha calibrated port 77therein "to control the flow of liquid fuel'to nozzle 37. It is to benoted that the valve 68 never seats against port 77, so that fuel isfree to pass through bore 36, even with all parts at rest, as shown inFig. 4.

At a point adjacent the upper end of hollow bore 70 I provide acalibrated orifice 78 in the stem 69 which opens into the fuel passage36 above piston 43. At a second determined point in the length of boreor passage 70, I provide a second calibrated orifice 79 which opensdirectly into the dash-pot chamber 40 below the piston 43. The lower endof the sleeve 49 is threaded and closed by a screw cap 80 threadedthereon and containing a gasket 80" to seal the joint. Within the sleeve49 is a helical spring 81 which is supported on cap 80 and which extendsupward into the hollow rack 65 and engages the shoulder 67 to keep therack in proper mesh with its pinion 64 and prevent back lash between therack and pinion.

The operation of my carburetor is as follows: When it is desired tostart the engine (not shown), to which the carburetor 1 is operativelyconnected, the parts being at rest as shown in Fig. 4, the throttle 9 isopened and the lever 58 is rotated counterclockwise of Fig. 3, whichwill lower the metering pin 68 into sleeve 74, controlling or cuttingoff the by-pass through the metering pin at orifice 7 9. If the engineis now started, the sub-atmospheric pressure created in the mixingchamber 6 will raise the air valve 31'; but this movement of valve 31will be very slow, due to the fact that fuel can pass tothe underside ofpiston 43 only through the clearance around the sides thereof, since thebypass or passage through the metering pin stem 69 by way of orifice 78,bore 70, and orifice 79, has been cut off by sleeve 74. However, sincefuel port 7 7 is opened wide by the lowering of the valve 68,- a verrich mixture of fuel from bore 36 and re atively little air 7 fromchamber 17 will be drawn into the mixing chamber 6 and fed to theengine. When the engine has started and the throttle 9 is moved towardclosed position, Fig. 4, the suction in the mixing chamber 6 will belowered, allowing the air valve 31 to drop. The air valve will closerapidly, due to the .upward opening check valves 45. Should it bedesired to warm up the engine, the metering pin may be left depressed tocut off the by-pass and the engine accelerated'and cut down severaltimes. On each acceleration the air valve 31 will open slowly and supplya rich mixture to the engine cylinders, as described for motor starting.After the engine '70 to opposite sides of piston 43, an

has been properly warmed up, the metering pin 68 is returned by theoperator to its normalrunning position, Fig. 4, by clockwise movement oflever 58 until arm 60 engages stop 61 and orifice 7 9 has been raisedout of sleeve 74. For normal running the metering pin by-pass throughorifice 78, passage 70, and orifice 79, is open so .thatthere isunrestricted communication through assage d liquid fuel may flow freelythrough the bypass from the dasht above the piston to the dash-potbeneat h the piston, or vice-versa, upon movement of piston 43. Thiswill permit the air valve 31 to open rapidly in response to the suctionin the mixing chamber,

- as it is substantially unretarded by piston 43 and will thereforesupply the necessary volume of air to the mixture to give the desiredthermal efliciency. When the by-pass is open, the motor will respondquickly to the throttle, because the quickly opening valve 31 will passa greater volume of air than when the y-pass is closed, and thereforesupply the required greater volume of mixture for rapid acceleration.

It will be understood from the foregoing description, that by the use ofmy improved carburetor, the operator can control the opening movement ofthe air valve 31 and therefore the vacuum within mixing chamber 6through the medium of the dash-pot by-pass. When the by-pass is closedby lowering the needle valve 68, the opening movement of the air valve31'will be additionally retarded,

causing a relatively higher vacuum in the mixing chamber, and since theport 77 will have been opened wider by the lowering of valve 68, therewill be a 'greaterdischargeof liquid fuel through calibrated orifice '37while the quantity of air admitted to the chamber 6 around valve 31 willbe comparatively small, resulting in a rich fuel mixture. The meteringpin 68 may be adjusted relative to a fixed position of the air valve 31by adj ustment of lever -58about shaft 54 to give suflicient fuel forcold motor operation; but in order to get a proper mixture which issufliciently rich for acceleration from low speeds ('5 to 10 miles perhour) to a speed at which the air valve 31 reaches its fixed position'(20 miles per hour), I provide the carburetor with my metering pinby-pass, whereby I am enabled to increase the drag of the dash-pot uponthe air valve 31 simultaneously with the adjustment of the metering'pin6'8, and thereby obtain efficient acceleration of a cold motor orengine. However, when the by-pass is open and the needle valve is theposition of normal carburetor operation, Fig. 4, then since liquid fuelcan readily pass from the space above the piston 43 through the by-passto the space in the chamber 40 below the pistion, or in response tothrottle positions lVhat I claim and desire to secure by Let- 'tersPatent of the United States is 1. A carburetor comprising a'casingincluding a mixing chamber having an airinlet, afuel inlet and athrottle-controlled mixture outlet, a suction operated, valve forcontrolling said air inlet, means for automatically regulating theopening and closing movements of said suction-operated valve, and meansunder the control of an o erator for increasing the area of't'he fuel inct an simultaneously decreasing the rate of opening movement of saidsuction-operated valve.

2. A carburetor comprising a casing ineluding a mixing chamber having anair inlet, a fuel inlet, and a throttle controlled mixture outlet, asuction operated valve for controlling said air inlet, a dash-potforautomatically regulating the opening and closing movements of saidsuction-operated valve, and means under the control of an operator forsimultaneously increasing the resistance of said dash-pot and the areaof said fuel inlet.

3. A carburetor comprising a casingincluding a mixing chamber having anan in-- let. a fuel inlet and a mixture outlet, an air valve for saidair inlet, means for retarding opening movement of said air valve, afuel valve for said fuel inlet, and means under the control of anoperator for operating said fuel valve to control the fuel supplyrelative to the air supply and simultaneously therewith to retard theopening movement of said air valve. I

4. A carburetor comprising a casing 1ncluding a mixing chamber having anair in let, a main fuel inlet and amixture outlet, a suction-operatedvalve for controlling said .airfinlet and said fuel inlet, a dash-potcham ber, a piston'in said dash-pot chamber and "coniiected"to, saidsuction-operated valve, *f gjmeanfs'iiig passing a fluid in saiddash-pot *c'ha'riiberffromone side to the other of said piston'to'regulate movement of said suction- ";Top'erlated valve-,and meansoperable to re- 'sti'ict -tlie fiovv'of said fluid from one side to "ytlieothero fsaid piston to retard opening *moveme'ntof said suctionoperated valve and joperableto increase the effective area of said'yiiiainj'fuelinl'etto increase flow of fuel to said 1 miiriiig'chamber, said last-named means bein'g operable, to reestablish flowpermitting morekrapid opening movementof said suc- EMA carburetorcomprising a casing ,in-

9' cluiilinga mining chamber having an air in let, a main fuel inlet anda mixture outlet,

ais'uction-operated valve for controlling said airinlet and said fuelinlet, a dash-pot chamber, a piston in said dash-potchamber andconnected to said suction-operated valve,

1 means for passing a fluid in said dash-pot chamber from one side tothe other of said piston to re ulate movement of said suction- 0 ratedIva ve, and slide valve means 0 era le manually to restrict the flow ofsaid uid from one side to thevother of said piston to retard openingmovement of said suction operated valve and operable to reestablishfiovv permitting more rapid opening movement of 's'aid suction-operatedvalve to de crease the flow of fuel to said mixing chamber.

' 6. A "carburetor comprising a mixing chamber having air and fuelinlets and a mixture outlet, a suction-operated valve conr trolling saidair inlet and said fuel inlet, a

dash-potchamber, a piston in said dash-pot chamber and. connected tosaid suction-operated valve to regulate movement thereof,

means to permit flow of fluid through said piston, and means manuallycontrolled for regulating said last-named means.

7 i A carburetor comprising a mixing chamber. having air and fuel inletsand a mixture outlet, a suction-operated valve controlling said airinlet and said fuel inlet, a dash-pot chamber, a piston in said dash-potchamber and connected to said suction-operated valve to regulatemovement thereof, a conduit member to permit flow of fluid through saidpiston, and manual means to close said conduit member to retard openingmovement of .said' suction-operatedv valve to increase flow of fuel tosaid mixing chamber.

8. A carburetor comprising a mixing chamber having air. and fuel inletsand a mixture outlet, a' suction-operated valve controlling said airinlet and having a. fuel pas-,

sage therein, a dash-pot chamber, a piston in said dash-pot chamber toregulate movement 95 of said valve, a fuel valve cooperating With saidfuel passage to regulate flow of fuel therethrough, said fuel valvecontaining a bypass opening on opposite sides of said is ton, and meansfor regulating flow of f nal through said by-pass.

9. A carburetor comprising a mixing chamber having air and fuel inletsand? a. mixture outlet, a suction-operated valve controlling said airinlet and having a fuel passage therein. a dash-pot chamber, a piston insaid dashnot chamber to regulate movement of'said valve, a fuel valvecooperating with said fuel passage to regulate flow of fuel therethrough, said fuel valve containing a by-pass opening on opposite sides ofsaid piston, and manual- 1y operable means for regulating flow of fuelthrough said by-pass.

10. A carburetorcomprising a casing including a. mixing chamber havingair and fuel inlets and a mixture outlet, a dash-pot chamber having apiston, a valve for said air inlet, means connecting said valve and saidpiston, and a metering-pin for said fuel inlet projecting through andslidable in said piston, said metering-pin having a passage to by-passfuel through said piston.

ll. A carburetor comprising a casing including a mixing chamber havingair and fuel inlets and a mixture outlet, a dash-pot chamber having apiston, a valve for said air inlet, means connecting said valve and saidpiston, a metering-pin for said fuel inlet projecting throughandslidable in said piston, said metering-pin having a passage to bypassfuel through said piston. and means to control said passage.

12. A carburetor comprising a casing including a mixing chamber havingan outlet and an air inlet, a valve for said air inlet and having astem, a dash-pot chamber having a reciprocable piston therein connectedto said stem, said stem having a hollow longitudinal bore communicatingwith said dash-pot chamber and with said mixing chamber, and areciprocable metering-pin projecting through said piston into said borefor cooperation therewith, said metering-pin having a by-pass forpassage of fuel from and to opposite sides of said piston.

13. A carburetor comprising a casing including a mixing chamber havin anoutlet and an air inlet, a valve for said air inlet and having a stem, adash-pot chamber having a reciprocable piston therein connected to saidstem, said stem having a hollow longitudinal bore communicating withsaid dash-pot chamber and with said mixing chamber, a reciprocablemetering-pin projecting through saidpiston into said bore forcooperation therewith, said metering pin having a bypass for passage offuel from and to opposite sides of said piston, and means to controlsaid by-pass upon reciprocation of said metering pin.

14. A carburetor comprising a casing including a mixing chamber havingan outlet whereby the rate of opening movement of having a stem, adash-pot chamber having a reciprocable piston therein connected to saidsi stem, said stem having a hollow longitudinal bore communicating withsaid dash-pot chamber and with said mixing chamber, a reciproeablemetering-pin projecting through said piston into said bore forcooperation-therewith, said metering pin having a by-pass for passage offuel from and to op osite sides of said piston, a sleeve surroun ingsaid metering pin adjacent said byass and having a sliding fit on saidmeterlug-pin, and means to move said meteringpin into said sleeve toclose said by-pass.

15. A carburetor comprising a casing including a mixing chamber havingan outlet and an air inlet, a suction-controlled air valve for said airinlet, a stem for said air valve having a longitudinal bore, a dash-potchamber into which said-valve stem projects, a piston on said valve stemin said dash-pot chamber, a fuel inlet to said dash-pot chamber, anaperture for admission of fuel to said bore, a fuel valve cooperablewith said bore and having a stem projecting through said piston, meansto move said fuel valv'e relative to said bore, said fuel valve stemhaving means for passage of fuel from and to ops posite sides of saidpiston, and means to cut off said passage means.

16. A carburetor comprising a casing having a mixing chamber and a mainair inlet to said chamber, an air valve controlling said air inlet, areciproca-ble fuel delivery member insaid air inlet and having a.passage therethrough for opening directly into saidmlxing chamber, ametering pin to regulatethe cross-sectional area of and extending intosaid passage, said air valve having operable engagement with said memberto control flow of fuel through said passage, a'dash pot eontrolling theopening movement of said air valve, and means to increase the resistanceof the dash-pot to opening movement of the air valve.

17. A carburetor comprising a casing having a mixing chamber and an airinlet to said chamber, an air valve having a stem and responsive tosuction in said mixing chamber for controlling said air inlet, said stemand valve having a passage therethrough for flow af fuel to saidmixingchamber, a metering pin to regulate the crossesectional area ofsaid passage, said 'air valve controlling flow of fuel through saidpassage, a dash-pot having a piston therein controlling the openingmovement of said'air valve. by-pass means normally establishing fuelflow from and to opposite sides of said piston, and manuallyoperablemeans to decrease the effective area of said by-pass meanswhereby to decrease the flow of fuel to the suction side of said pistonupon opening movement of the air valve In testimony gned my name and anair inlet, a valve for said air inlet and said air valve is decreased.

whereof I have-"hereunto WA TEaH; WEBER.

